Abstract: The process for producing a photochromic eyewear lens by forming at least a layer of modified photochromic poly(urea-urethane) by combining photochromic material and the reaction product of a polyurethane pre-polymer and a mixture of diethyltoluene diamine and one or more polyols, plus catalyst. The mixture comprises both NH2 and OH reactive groups, with at least 0.04 equivalent weights of OH reactive species available for reaction with each 1.0 equivalent weight of excess NCO reactive species available in the pre-polymer. The lens comprising the modified photochromic poly(urea-urethane) can exhibit faster fade-back rates and better photochromic performance than lenses with non-modified poly(urea-urethane).

Abstract: A process for producing a photochromic eyewear lens. In one embodiment at least a layer of modified photochromic poly(urea-urethane) is formed by combining photochromic material and the reaction product of a polyurethane pre-polymer and a mixture of diethyltoluene diamine and one or more polyols, plus catalyst. The mixture comprises both NH2 and OH reactive groups, with at least 0.04 equivalent weights of OH reactive species available for reaction with each 1.0 equivalent weight of excess NCO reactive species available in the pre-polymer. The lens comprising the modified photochromic poly(urea-urethane) can exhibit faster fade-back rates and better photochromic performance than lenses with non-modified poly(urea-urethane).

Abstract: A process for producing a photochromic eyewear lens. In one embodiment at least a layer of modified photochromic poly(urea-urethane) is formed by combining photochromic material and the reaction product of a polyurethane pre-polymer and a mixture of diethyltoluene diamine and one or more polyols, plus catalyst. The mixture comprises both NH2 and OH reactive groups, with at least 0.04 equivalent weights of OH reactive species available for reaction with each 1.0 equivalent weight of excess NCO reactive species available in the pre-polymer. The lens comprising the modified photochromic poly(urea-urethane) can exhibit faster fade-back rates and better photochromic performance than lenses with non-modified poly(urea-urethane).